Reuters apparently talked to the mastermind behind the Jakarta attacks on Telegram back in November

Police
officers react near the site of a blast in Jakarta, Indonesia,
January 14, 2016.REUTERS/Darren
Whiteside

JAKARTA (Reuters) - Seven years ago, Bahrun Naim was quietly
running an Internet cafe in the small Indonesian city of Solo.

On Thursday he was identified by police as the mastermind behind
the deadly attack on Jakarta claimed by Islamic State, pulling
the strings from Raqqa, the radical group's de facto capital in
Syria.

In between, Naim was arrested in 2011 for illegal arms possession
and jailed for three years, and police say that since then he has
emerged as a key player in militant networks that have sprouted
around Solo and across Central Java.

A year ago, he left for Syria to join the frontlines of Islamic
State, and police believe Naim was closely involved in
coordinating Thursday's assault.

Five of the attackers and two civilians were killed in Islamic
State's first strike against Indonesia, the world's most populous
Muslim nation where the group wants to establish an Asian
beachhead for its "caliphate".

There had been hints of what was to come for weeks.

After the coordinated attacks across Paris in November, the
militant intellectual published a blog in which he explained to
his followers how it was easy to move jihad from "guerrilla
warfare" in Indonesia's equatorial jungles to a city.

Reuters contacted Naim on Nov. 24 on Telegram social messaging,
using details provided by one of his acquaintances. In that
exchange, he said there were more than enough Islamic State
supporters to "carry out an action" in Indonesia.

"Just waiting for the right trigger," the man identifying himself
as Naim said.

Naim could not be reached for comment on Thursday.

Intelligence experts say that, not long after that Telegram
exchange, intelligence officials began to pick up talk in social
messaging chatrooms that an attack on Indonesia was imminent.

"Chatter among Islamists began to become more organized last
month and there were discussions for the first time of a multiple
attack," said a Jakarta-based security adviser, who monitors
radical group discussions on mobile messaging services for the
government.

Counter-terrorism officials believe there are at least 1,000
sympathizers of the radical jihadist group across Indonesia.

Military
armored personnel carriers are seen near the site of an attack in
central Jakarta January 14, 2016.Reuters/Darren Whiteside

Emerging militant networks

The eavesdropping helped lead police to the arrest of more than a
dozen men across the populous island of Java who were suspected
of planning attacks over the Christmas and New Year holidays.

Bomb-making materials, a suicide vest and "jihad manuals" were
found during the raids. Police said some of those rounded up had
received funding and support from Naim, who believes Indonesia
should be governed strictly as an Islamic country.

Naim had been planning the attack on Indonesia's capital for a
while, Jakarta Police Chief Tito Karnavian said on Thursday,
adding that he clearly had ambitions to become "the leader" of
Islamic State in Southeast Asia.

Sidney Jones, a Jakarta-based expert on Islamist militants at the
Institute for Policy Analysis of Conflict, said in a November
report that there was only a slim chance in Indonesia of an
attack on the scale seen in Paris, but she warned then that the
threat was growing under the government's nose.

Residents
drive across a street with a fluttering Islamic State flag, in
Tel Abyad town on the Syrian-Turkish border, Raqqa
countryside.Thomson
Reuters

She noted that in one blog post, entitled "Lessons from the Paris
Attacks", Naim urged his Indonesian audience to study the
planning, targeting, timing, coordination, security and courage
of the Paris jihadis.

That said, experts have pointed out that the relatively low death
toll in the Jakarta assault suggested the involvement of local,
poorly armed militants with little or no training.

In the Telegram exchange with Reuters, Naim also spoke of more
mundane affairs, explaining that he enjoyed life in Syria and had
no plans to return to Indonesia.

"I move around, depending on where our emir orders us to go. It's
good here in Syria. There's electricity, accommodation, water and
it's free. The services provided by them are good, cheaper than
in Indonesia," he said.